The amount of time it takes – after cutting calories – to lose weight depends on your daily calorie deficit. Although you can lose weight rapidly by drastically reducing calories, a safer strategy will help you start losing weight in about three to seven days. Adding exercise to your weight-loss regimen helps you tone up and burn extra fat while losing weight.

Time Frame

A safe weight loss is 1 to 2 pounds weekly, notes the Centers for Disease Control and Prevention. Following this weight-loss strategy by reducing your current intake by 500 to 1,000 calories daily means you might start to notice a weight change on the scale in about three to seven days. Weighing yourself at the same time each day – such as right away when you wake up – will give you the most accurate reading.

Considerations

If you notice that you’re losing a pound -- or more – in just one day, you’re most likely losing water weight. Drinking too little water or drastically cutting carbohydrates can lead to daily water-weight fluctuations, which doesn’t give you an accurate result when you step on the scale. To lose 1 pound of body fat, you have to burn off 3,500 calories more than you eat -- and it’s unsafe to attempt this feat in just one day.

Exceptions

If you’re obese, have immediate risks for developing chronic health conditions and your doctor gives you the OK, a very low-calorie diet, consisting of 500 to 800 calories daily may be appropriate if you follow it under medical supervision. Following very low-calorie diets can cause you to lose up to 5 pounds in just one week, meaning that you could start to notice a change on the scale just two or three days after beginning your diet. However, VLCDs are only safe when supervised by a qualified medical professional.

Effects from Exercise

If you begin an exercise program as a way to create a 500- to 1,000-calorie daily deficit, you may not lose weight at all in the first week or two. This is because you’re likely building muscle mass – especially if you’re weight training regularly – which weighs more than body fat. To get a more accurate reading of the effects of beginning a new exercise program, track the circumference of your waist, hips, thighs and arms in addition to weighing yourself one time weekly. Even if you aren’t losing weight, you should notice a reduction in body fat in just one to two weeks.

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About the Author

Erin Coleman is a registered and licensed dietitian. She also holds a Bachelor of Science in dietetics and has extensive experience working as a health writer and health educator. Her articles are published on various health, nutrition and fitness websites.